1. Field of the Invention
The present invention relates to an optically transparent pressure sensitive adhesive sheet for heat transfer image pattern formation and an optically transparent decorative pressure sensitive adhesive sheet. Specifically, the present invention relates to an optically transparent pressure sensitive adhesive sheet for use in heat transfer image pattern formation which is transparent to visible light and is suitable for use in the production of a decorative pressure sensitive adhesive sheet that is used in such a manner as to be affixed to window glass, a plastic board for a window or a transparent partition employed in a room, and an optically transparent decorative pressure sensitive adhesive sheet produced with the optically transparent pressure sensitive adhesive sheet.
2. Description of the Related Arts
Plastic films having various functions have been used so as to be affixed to window glass, plastic boards for windows, etc. For example, affixed to show-windows, windows of buildings, windows of vehicles, etc. are films having one or more of the functions to shield ultraviolet radiation or infrared radiation, to prevent scattering of broken pieces of the windows, to prevent seeing through inside the windows and to decorate the windows.
Among those films, as decorative films on the surfaces of which various patterns are formed, available are only those produced on a large scale, such as those produced by silk screen process printing. However, users desire the realization of the easy and small scale production of decorative films having original designs so as to express their originalities.
Various computer-controlled printing methods are considered to satisfy the above-mentioned desire.
Such printing methods include the electrophotographic method, the ink jet method, the heat transfer method, etc. Among those methods, the heat transfer method is the most preferable for the reasons that operation and maintenance are easy, down sizing of the apparatuses and reducing costs are possible, running costs are low, no noises are generated, it is easy to impart durability for outdoor use, and so forth.
However, it was heretofore impossible to obtain clear image patterns by making printing on conventional films for windows with heat transfer type printers.
In view of the above, the object of the present invention is to provide an optically transparent decorative pressure sensitive adhesive sheet which is transparent to visible light and has a heat-transferred image pattern and good decorative characteristics and which is used in such a manner as to be affixed to window glass, a plastic board for a window or a transparent partition employed in a room, and to provide an optically transparent pressure sensitive adhesive sheet for use in heat transfer image pattern formation which is suitable for the production of the optically transparent decorative pressure sensitive adhesive sheet.
As a result of intensive research and development made by the inventors of the present invention in order to achieve the above-mentioned object, it has been found that the foregoing object can be attained by the use, as the optically transparent pressure sensitive adhesive sheet for heat transfer image pattern formation, of a pressure sensitive adhesive sheet comprising an optically transparent film on which a heat transfer image pattern can be formed and an antistatic release sheet laminated on the optically transparent film via a pressure sensitive adhesive layer, and by the use, as the optically transparent decorative pressure sensitive adhesive sheet, of such a pressure sensitive adhesive sheet in which a heat transfer image pattern is formed on the optically transparent film or such a pressure sensitive adhesive sheet in which the antistatic release sheet is removed and a functional film with a pressure sensitive adhesive layer on the back is laminated on the optically transparent film on the side where the antistatic release sheet has been removed. The present invention has been made based on the above findings.
Specifically, the present invention provides:
(1) an optically transparent pressure sensitive adhesive sheet comprising an optically transparent film which enables an image pattern to be heat-transferred thereonto and an antistatic release sheet laminated, via a pressure sensitive adhesive layer, on the side opposite to a heat transfer image pattern-receiving side of the optically transparent film;
(2) an optically transparent decorative pressure sensitive adhesive sheet in which an image pattern is formed by heat transfer method on the heat transfer image pattern-receiving side of the optically transparent film in the optically transparent pressure sensitive adhesive sheet set forth in the above paragraph (1);
(3) an optically transparent decorative pressure sensitive adhesive sheet, wherein a transparent functional film is laminated on that side of the optically transparent film on which the image pattern is formed in the optically transparent decorative pressure sensitive adhesive sheet set forth in the above paragraph (2);
(4) an optically transparent decorative pressure sensitive adhesive sheet, wherein the optically transparent decorative pressure sensitive adhesive sheet which is set forth in the above paragraph (2) or (3) but in which the antistatic release sheet has been removed and the pressure sensitive adhesive layer has been exposed is laminated, via thus exposed pressure sensitive adhesive layer, on one side of a transparent functional film having a pressure sensitive adhesive layer on the other side thereof; and
(5) an optically transparent decorative pressure sensitive adhesive sheet set forth in the above paragraph (3) or (4), wherein the transparent functional film is a stainproof film, a metal-deposited film, an infrared cut-off film, a mat-textured film or a differently viewing film.
An optically transparent pressure sensitive adhesive sheet for heat transfer image pattern formation according to the present invention enables a heat transfer image pattern having good quality to be readily formed by the heat transfer method, and has transmission with respect to visible light.
With the use of an optically transparent pressure sensitive adhesive sheet for heat transfer image pattern formation according to the present invention, which enables easy formation of a heat transfer image pattern, there can be obtained a decorative pressure sensitive adhesive sheet that has good decorative characteristics and is transparent to visible light and that is used for decorative purposes in such a manner as to be affixed to window glass, a plastic board for a window or a transparent partition employed in a room.